Question

Phân tích các đa thức sau thành nhân tử:

a) R=bc(a+d)(b-c)-ac(b+d)(a-c)+ab(c+d)(a-b)

b) A=(a+b)(b+c)(c+a)+abc

c) B=x²y+xy²+x²z+xz²+y²z+yz²+2xyz

Answer 1

b: \(=\left(ab+ac+b^2+bc\right)\left(c+a\right)+abc\)

\(=abc+a^2b+ac^2+a^2c+b^2c+b^2a+bc^2+abc+abc\)

\(=ab\left(a+b\right)+abc+bc\left(b+c\right)+abc+ac\left(a+c\right)+abc\)

\(=ab\left(a+b+c\right)+bc\left(b+c+a\right)+ac\left(a+b+c\right)\)

\(=\left(a+b+c\right)\cdot\left(ab+bc+ac\right)\)

c: